Heterocyclic compounds

ABSTRACT

The invention is concerned with novel compounds of the formula ##STR1## wherein R 1 , R 2 , R 3 , R 4 , R 5  and R 6  have the significances given in the description, as well as enol ethers and salts thereof and their manufacture, weed control compositions which contain such compounds as active substances and the use of the active substances or compositions for the control of weeds. The invention is also concerned with certain starting materials which have herbicidal activity and with weed control compositions containing these.

The present invention is concerned with heterocyclic compounds, namely3-aryluracils of the general formula ##STR2## wherein

R¹ signifies hydrogen, C₁₋₄ -alkyl, C₃ or 4 -alkynyl, C₃ or 4 -alkynylor C₁₋₄ -haloalkyl,

R² signifies a group ##STR3## or, where R¹ signifies haloalkyl, alsohydrogen, C₁₋₈ -alkyl, C₂₋₈ -alkenyl, C₂₋₈ -alkynyl or C₂₋₈-alkoxyalkyl,

R³ signifies halogen or cyano,

R⁴ signifies hydrogen or halogen,

R⁵ signifies hydrogen, fluorine or C₁₋₄ -alkyl,

R⁶ signifies C₁₋₄ -alkyl or C₁₋₄ -haloalkyl, the symbols R⁷ eachindependently signify hydrogen or C₁₋₃ -alkyl and

n signifies 0, 1 or 2, and

Q signifies a saturated three- to seven-membered carbocyclic orheterocyclic residue which is optionally substituted with one or moreC₁₋₄ -alkyl residues, whereby the heterocyclic residue has 1 or 2 heteroatoms selected from oxygen and sulphur and optionally a keto function inthe ring, or

Q signifies a phenyl residue which is optionally mono- ormultiply-substituted with halogen, C₁₋₄ -alkyl, C₁₋₄ -haloalkyl, C₁₋₄-alkoxy, C₁₋₄ -alkylthio, nitro and/or cyano and which additionally cancontain a fused, saturated, carbocyclic or heterocyclic five- toseven-membered ring, whereby the heterocycle has 1 or 2 oxygen atoms inthe ring,

and the corresponding enol ethers of those compounds of formula I inwhich R¹ is different from hydrogen or C₁₋₄ -haloalkyl as well as saltsof those compounds of formula I in which R¹ or R² signifies hydrogen.

Under the aforementioned enol ethers there are thus to be understood thecompounds of the formula ##STR4## wherein R³, R⁴, R⁵, R⁶, R⁷, n and Qhave the significances given above and R^(1') signifies C₁₋₄ -alkyl, C₃or 4 -alkenyl or C₃ or 4 -alkynyl.

The compounds in accordance with the invention have herbicidal activityand are suitable as active substances of weed control compositions.Accordingly, the invention also includes weed control compositions whichcontain compounds in accordance with the invention as the activesubstance, a process for the manufacture of these compounds as well asthe use of the compounds or compositions for the control of weeds.

In formula I above "halogen" embraces fluorine, chlorine, bromine andiodine. The alkyl, alkenyl and alkynyl residues can be straight-chain orbranched and this also applies to the alkyl part of the haloalkyl,alkoxy and alkylthio groups. A haloalkyl group can have one or more(similar or different) halogen atoms.

The following are examples of residues Q: Cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, 2-oxiranyl, 2-methyl-2-oxiranyl,3-oxetanyl, 3-methyl-3-oxetanyl, 3-ethyl-3-oxetanyl, 2-tetrahydrofuryl,3-tetrahydrofuryl, 2-tetrahydropyranyl, 3-tetrahydropyranyl,4-tetrahydropyranyl, 3-methyl-3-thietanyl, 3-tetrahydrothienyl,1,3-dioxolan-5-yl, 1,3-dioxan-5-yl, 1-oxo-4-tetrahydrothiopyranyl,phenyl, 1,3-benzodioxol-5-yl and 1,3-benzodioxan-6-yl.

The salts of the compounds of formula I are especially alkali metalsalts, e.g. sodium and potassium salts; alkaline earth metal salts, e.g.calcium and magnesium salts; ammonium salts, i.e. unsubstituted ammoniumsalts and mono- or multiply-substituted ammonium salts, e.g.triethylammonium and methylammonium salts, as well as salts with otherorganic bases, e.g. with pyridine.

The presence of at least one asymmetric carbon atom in the compounds offormula I means that the compounds can occur in optically isomericforms. Geometric isomerism can also occur when an aliphatic C═C doublebond is present. Formula I is intended to embrace all of these possibleisomeric forms as well as mixtures thereof.

An interesting group of compounds in accordance with the inventioncomprises those compounds of formula I in which R¹ signifies hydrogenC₁₋₄ -alkyl, C₃ or 4 -alkenyl or C₃ or 4 -alkynyl and the enol ethersand salts of these compounds. A further interesting group of compoundsin accordance with the invention comprises those compounds of formula Iin which R¹ signifies C₁₋₄ -haloalkyl, R² signifies hydrogen, C₁₋₈-alkyl, C₂₋₈ -alkenyl, C₂₋₈ -alkynyl, C₂₋₈ -alkoxyalkyl or a group -(CR⁷R⁷)_(n) -Q and Q signifies either a saturated three- to seven-memberedcarbocyclic or heterocyclic residue which is optionally substituted withone or more C₁₋₄ -alkyl residues, whereby the heterocyclic residue has 1or 2 hetero atoms selected from oxygen or sulphur in the ring, or aphenyl residue which is optionally mono- or multiply-substituted withhalogen, C₁₋₄ -alkyl, C₁₋₄ -haloalkyl, C₁₋₄ -alkoxy, C₁₋₄ -alkylthio,nitro and/or cyano, and the salts of these compounds.

If R¹ signifies C₃ or 4 -alkenyl or C₃ or 4 -alkynyl, this residue ispreferably allyl or propargyl. Where R⁶ signifies haloalkyl, this ispreferably trifluoromethyl or pentafluoroethyl. In general a halogenatom which may be present is preferably fluorine, chorine or bromine.

Independently of one another R¹ preferably signifies straight-chain C₁₋₄-alkyl, especially methyl, or C₁₋₄ -fluoroalkyl, especiallydifluoromethyl; R³ preferably signifies chlorine or bromine; R⁴preferably signifies hydrogen or fluorine; R⁵ preferably signifieshydrogen, fluorine or methyl; R⁶ preferably signifies C₁₋₄ -alkyl,especially methyl; each R⁷ preferably signifies hydrogen; and npreferably signifies 0 or 1.

Especially preferred compounds of formula I are the cycloheptyl,3-tetrahydrofuryl, 1,3-dioxan-5-yl, cyclopropylmethyl,tetrahydrofurfuryl, 1,3-dioxolan-4-ylmethyl, benzyl,4,4-dimethyl-2-oxo-tetrahydrofuran-3-yl, cyclopentyl, 1-cyclopropylethyland cyclohexyl esters of2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoicacid.

Further representatives of compounds of formula I are the 3-nitrobenzyl,α,α-dimethylbenzyl, tetrahydrothiophen-3-yl, 4-cyanophenyl and3,5-di(trifluoromethyl)benzyl esters of2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoicacid as well as the cyclopropylmethyl, 1-cyclopropylethyl, cyclopentyl,cyclohexyl, cycloheptyl, 3-tetrahydrofuryl, 1,3-dioxan-5-yl,1,3-dioxolan-4-ylmethyl, benzyl and tetrahydrofurfuryl esters of2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoicacid.

Especially preferred compounds of formula I in which R¹ signifies C₁₋₄-haloalkyl are:

Isopropyl2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate,

2-chloro-5-[3-difluoromethyl-3,6-dihydro4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoic acid,

isopropyl5-[4-ethyl-3-difluoromethyl-3,6-dihydro-2,6-dioxo-1(2H)-pyrimidinyl]-2-chloro-4-fluorobenzoate,

isopropyl5-[4-ethyl-3-difluoromethyl-3,6-dihydro-2,6-dioxo-1(2H)-pyrimidinyl]-2-bromo-4-fluorobenzoate,

isopropyl2-bromo-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate,

2-propynyl-2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoateand

methyl 2-chloro-5-[3-difluoromethyl-36-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate.

Further representatives of such compounds of formula I are the ethyl,n-propyl, n-butyl, n-hexyl n-octyl, sec.-butyl, 1-methylbutyl,neopentyl, isobutyl, isopentyl, 2-methylbutyl, 1,2-dimethylpropyl,tert.butyl, 1-ethylpropyl, allyl, 2-butenyl, 3-methyl-2-butenyl,3-methyl-3-butenyl 1-ethyl-2-propenyl, 4-pentenyl, 1-methyl-2-butenyl,1-methyl-3-butenyl, 3-butenyl, 2-methyl-2-propenyl, 3-butynyl,2-butynyl, methoxymethyl, ethoxymethyl, n-propoxymethyl,isopropoxymethyl, n-pentyloxymethyl, 1-methoxyethyl, 2-methoxyethyl2-ethoxyethyl, 2-isopropoxyethyl, 2-methoxy-1-methylethyl,2-n-butyloxyethyl, cyclopentyl, cyclohexyl, cycloheptyl,cyclopropylmethyl, 1-cyclopropylethyl, 3-tetrahydrofuryl,tetrahydrofurfuryl, 1,3-dioxan-5-yl, 1,3-dioxolan-5-ylmethyl, benzyl and4-methoxyphenyl esters of2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoicacid, isopropyl2-chloro-5-[3-difluoromethyl-3,6-dihydro-4,5-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate,isopropyl2-chloro-5-[3-difluoromethyl-3,6-dihydro-5-fluoro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate,isopropyl 2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-26-dioxo-1(2H)-pyrimidinyl]-benzoate and isopropyl2-chloro-5-[3,6-dihydro-4-methyl-3-(1,1,2,2-tetrafluoroethyl)-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate.

The process in accordance with the invention for the manufacture of thecompounds of formula I and of their enol ethers as well as salts ischaracterized by

(a) for the manufacture of those compounds of formula I in which R¹signifies hydrogen as well as, if desired, of metal salts of thesecompounds, subjecting a compound of the general formula ##STR5## whereinR³, R¹, R⁵, R⁶, R⁷, n and Q have the significances given above and R⁸signifies lower alkyl, preferably C₁₋₄ -alkyl,

to a cyclization under basic conditions and, if desired, converting ametal salt of the uracil derivative of formula I which may be obtainedinto the acid form (R¹ =hydrogen) by treatment with an acid,

(b) for the manufacture of those compounds of formula I in which R¹signifies C₁₋₄ -alkyl, C₃ or 4 -alkenyl, C₃ or 4 -alkynyl or C₁₋₄-haloalkyl, whereby R² is different from hydrogen when R¹ signifies C₁₋₄-haloalkyl, subjecting a uracil derivative of the general formula##STR6## wherein R², R³, R⁴, R⁵ and R⁶ have the significances givenabove,

to an alkylation with a corresponding alkylating agent containing a C₁₋₄-alkyl, C₃ or 4 -alkenyl or C₃ or 4 -alkynyl group, with the provisothat in the manufacture of a compound of formula I in which R¹ signifiesC₁₋₄ -haloalkyl R² in formula I' is different from hydrogen,

(c) for the manufacture of those compounds of formula I in which R¹ isdifferent from hydrogen and of the corresponding enol ethers,esterifying a benzoic acid of the general formula ##STR7## wherein R³,R⁴, R⁵ and R⁶ have the significances given above and R^(1") signifiesC₁₋₄ -alkyl, C₃ or 4 -alkenyl, C₃ or 4 -alkynyl or C₁₋₄ -haloalkyl,

or the corresponding enol ether, whereby the benzoic acid or its enolether can be present in the form of a reactive derivative, with ahydroxy compound of the general formula

    R.sup.2 OH                                                 IV

wherein R² has the significance given above with the proviso that in themanufacture of a compound of formula I in which R¹ signifies C₁₋₄-haloalkyl R² in formula IV is different from hydrogen,

or with a reactive derivative of this hydroxy compound,

(d) for the manufacture of those compounds of formula I in which R¹ isdifferent from hydrogen, subjecting a benzoic acid ester of the generalformula ##STR8## wherein R¹ ", R³, R⁴, R⁵ and R⁶ have the significancesgiven above and R⁹ signifies C₁₋₆ -alkyl, C₂₋₄ -alkenyl, C₂₋₄ -alkynylor C₂₋₆ -alkoxyalkyl,

to a trans-esterification reaction with a hydroxy compound of formula IVgiven above, whereby the reagent IV has a higher boiling point than thealkanol, alkenol or alkynol R⁸ OH, or

(e) for the manufacture of those compounds of formula I in which R¹signifies C₁₋₄ -haloalkyl and R signifies hydrogen, hydrolyzing abenzoic acid ester of the general formula ##STR9## wherein R³, R⁴, R⁵and R⁶ have the significances given above and R'" signifies C₁₋₄-haloalkyl and R^(2') has the significance of R² with the exception ofhydrogen,

to the corresponding benzoic acid,

(f) for the manufacture of the enol ethers of the compounds of formulaI, treating a uracil derivative of the general formula ##STR10## whereinR³, R⁴, R⁵, R⁶, R⁷, n and Q have the significances given above and Halsignifies chlorine or bromine,

with an alkanol, alkenol or alkynol R^(1') OH in the presence of anorganic base or with the corresponding alcoholate, alkenolate oralkynolate of the general formula

    R.sup.1' O.sup.⊖ M.sup.⊕                       VII

wherein R^(1') has the significance given above and M.sup.⊕ signifies anequivalent of a metal ion.

and, if desired, converting a thus-obtained compound of formula I inwhich R¹ or R² signifies hydrogen into a salt.

The cyclization according to process variant (a) can be carried outconveniently by treating the compound of formula II in an inert proticorganic solvent such as an alcohol, e.g. methanol, ethanol orisopropanol; an inert aprotic organic solvent such as an aliphatic orcyclic ether, e.g. 1,2-dimethoxyethane, tetrahydrofuran or dioxan or anaromatic, e.g. benzene or toluene; an inert aprotic, polar organicsolvent, e.g. dimethylformamide or dimethyl sulphoxide, whereby suchsolvents can be optionally used in a two-phase mixture with ahydrocarbon, e.g. n-hexane or toluene; or water with a base attemperatures between -78° C. and the reflux temperature of the reactionmixture. As bases there preferably come into consideration sodiumalcoholates, alkali metal hydroxides, especially sodium hydroxide andpotassium hydroxide, alkali metal carbonates, especially sodiumcarbonate and potassium carbonate, and sodium hydride. Where an alkanolis used as the solvent, this solvent conveniently corresponds to therespective hydroxy compound Q-(CR⁷ R⁷)_(n) -OH; thereby undesiredconcurrent trans-esterification reactions are avoided. When sodiumhydride is used as the base, the solvent is preferably an aliphatic orcyclic ether, dimethylformamide or dimethyl sulphoxide, whereby any ofthese solvents can be used in admixture with toluene.

Where one of the above-mentioned bases or the like is used, aftercompletion of the cyclization the product is present in the form of thecorresponding alkali metal salt. This can be isolated and purified in amanner known per se or the mixture can be acidified in order to isolatethe respective compound of formula I itself. For this purpose there ispreferably used a mineral acid such as hydrochloric acid or a strongorganic acid such as acetic acid or p-toluenesulphonic acid.

In process variant b) the term "alkylation" stands for the substitutionof the hydrogen atom of the N¹ -atom of the uracil nucleus with a C₁₋₄-alkyl, C₃ or 4 -alkenyl, C₃ or 4 -alkynyl or C₁₋₄ -haloalkyl group. Asthe alkylating agent there is conveniently used a C₁₋₄ -alkyl, C₃ or 4-alkenyl or C₃ or 4 -alkynyl halide, especially the respective chlorideor bromide, or sulphate, or a multiply-halogenated C₁₋₄ -alkane such as,for example, chlorodifluoromethane or a mono- or multiply-halogenatedalkene such as, for example, tetrafluoroethene.

The alkylation is conveniently carried out in the presence of an inert,protic organic solvent such as lower alkanol, e.g. ethanol, optionallyin admixture with water; an inert, aprotic organic solvent such as analiphatic or cyclic ether, e.g. 1,2-dimethoxyethane, tetrahydrofuran ordioxan; a ketone, e.g. acetone or butan-2-one; or an inert, aprotic,polar organic solvent, e.g. dimethylformamide, dimethyl sulphoxide oracetonitrile, as well as in the presence of a base such as sodiumhydride, an alkali metal hydroxide, especially sodium or potassiumhydroxide, an alkali metal alcoholate, especially sodium alcoholate, oran alkali metal carbonate or bicarbonate, especially sodium carbonate,potassium carbonate, sodium bicarbonate or potassium bicarbonate, attemperatures between 0° C. and the reflux temperature of the reactionmixture preferably at room temperature, or, in the case of thesubstitution of the hydrogen atom of the N¹ atom with a C₁₋₄ -haloalkylgroup, preferably at temperatures between 50° C. and 100° C. In apreferred embodiment the uracil derivative of formula I' is firstlytreated with the base such as sodium hydride, ethanolate or carbonate inthe solvent and after a short reaction period is treated with the halidein the same solvent. In a further embodiment the uracil derivative I' isbrought to reaction together with a dialkyl sulphate in the presence ofan alkali metal bicarbonate, especially sodium or potassium bicarbonate,in the solvent, e.g. acetone, at the reflux temperature. The reactionhas generally finished, depending on the solvent which is used, within arelatively short time or after several hours.

Process variant (c) is an esterification of the benzoic acid or of theenol ether or of a reactive derivative thereof, which can be carried outaccording to methods known per se. Thus, for example, a salt of abenzoic acid of formula III or of the corresponding enol ether isreacted with a halide, especially chloride, bromide or iodide, or thesulphate, mesylate or tosylate of the hydroxy compound IV in an inertdiluent at temperatures between room temperature and 100° C., e.g. atthe reflux temperature of the reaction mixture, preferably in thetemperature range of 40° C. to 70° C. As salts of the benzoic acid offormula III or of the corresponding enol ether there come intoconsideration especially alkali metal salts, e.g. the sodium, potassiumor lithium salt, alkaline earth metal salts, e.g. the magnesium, calciumor barium salt and salts with orhanic bases such as tertiary amines,e.g. triethylamine, 1,5-diaza-bicyclo[4,3,0]non-5-ene,1,8-diaza-bicyclo[5,4,0]undec-7-ene and 1,4-diaza-bicyclo[2,2,2]octane,with the alkali metal salts, especially the sodium salt and thepotassium salt, being preferred. The diluents which can be used arepreferably. inert organic solvents such as lower alkanols, e.g. ethanol,aliphatic and cyclic ethers e.g. diethyl ether, 1,2-dimethoxyethane,tetrahydrofuran and dioxan ketones, e.g. acetone and 2-butanone,dimethylformamide, dimethyl sulphoxide, acetonitrile andhexamethylphosphoric acid triamide. The salt can be produced in situ byreacting the acid with a suitable inorganic base, e.g. an alkali metalor alkaline earth metal carbonate or bicarbonate, hydroxide or hydride,or organic base to give the salt and subsequently allowing this to reactin the same reaction medium with the second reaction partner.

When an acid halide of the benzoic acid of formula III or of thecorresponding enol ether is used as the reactive derivative, this isconveniently reacted with the hydroxy compound of formula IV in an inertorganic solvent such as an aliphatic or cyclic ether, e.g. diethylether, 1,2-dimethoxyethane, tetrahydrofuran or dioxan, an aliphatic oraromatic hydrocarbon e.g. n-hexane, benzene or toluene, or ahalogenated, especially chlorinated, hydrocarbon, e.g. methylenechloride, chloroform or carbon tetrachloride, at temperatures from about-20° C. to 100° C. preferably from 0° C. to 50° C. Moreover, thereaction is conveniently carried out in the presence of an acid-bindingagent such as an organic base, e.g. triethylamine, pyridine,1,5-diaza-bicyclo[4,3,0]non-5-ene, 1,8-diaza-bicyclo[5,4,0]undec-7-eneor 1,4-diaza-bicyclo[2,2,2]octane. The acid halide is preferably theacid chloride.

As further reactive derivatives of the benzoic acid of formula III or ofthe corresponding enol ether there are to be mentioned the correspondingO-acyl-1,3-dicyclohexylisourea and the corresponding N-acylimidazole oracid anhydride. Such derivatives can be reacted, like the acid halide,with the hydroxy compounds of formula IV in order to proceed to thedesired benzoic acid esters. In these cases, however, the use of anacid-binding agent is unnecessary.

The reaction according to process variant (d) can be carried outconveniently by heating the benzoic acid ester of formula V in excesshydroxy compound of formula IV in the presence of a basic catalyst suchas sodium cyanide, preferably at the reflux temperature of the reactionmixture. In the course of the reaction the residue R⁹ of the benzoicacid ester V is replaced by the group R² of the hydroxy compound IV,whereby the alkanol, alkenol or alkynol R² OH, which has a lower boilingpoint, is liberated.

The hydrolysis of the benzoic acid ester I" according to process variant(e) can be carried out according to methods known per se, especiallyusing a strong mineral acid such as sulphuric acid or a base such analkali metal or alkaline earth metal hydroxide, e.g. sodium hydroxide orpotassium hydroxide, and optionally in the presence of an organicsolvent such as an alcohol, e.g. methanol or ethanol, or a chlorinatedhydrocarbon, e.g. methylene chloride, if desired also in admixture withwater. The hydrolysis is conveniently effected at temperatures between-20° C. and 100° C. preferably at room temperature. Where the product ispresent as a salt after alkaline hydrolysis, this can be isolated, forexample, by simply evaporating the solvent. The free acid can then beobtained by acidifying the salt with an acid preferably a mineral acid,e.g. hydrochloric acid or sulphuric acid.

In process variant (f) the term "metal ion" stands especially for analkali metal ion, e.g. the sodium or potassium ion, or an alkaline earthmetal ion, e.g. the calcium or magnesium ion. The sodium ion is thepreferred metal ion. Where the alkanol alkenol or alkynol R^(1') OH isused, pyridine is the especially suitable organic base.

The reaction is conveniently effected in an excess of the correspondingalcohol R^(1') OH as the diluent and at temperatures between 0° C. and50° C., preferably at room temperature.

Insofar as they can not be manufactured directly by the above-describedcyclization which is carried out under basic conditions, the desiredsalts of the compounds of formula I in which R¹ or R² signifies hydrogencan also be manufactured from these compounds I in a manner known per sesuch as, for example, by dissolving the compound of formula I in asolution of a respective inorganic or organic base. The salt formationis generally effected within a short time at room temperature. In oneembodiment the sodium salt is manufactured by dissolving the uracilderivative I in aqueous sodium hydroxide solution at room temperature,with equivalent amounts of the uracil derivative and of sodium hydroxidebeing used. The solid salt can then be isolated by precipirarion with asuitable inert solvent or by evaporation of the solvent. A furtherembodiment comprises introducing an aqueous solution of an alkali metalsalt of the uracil derivative I into an aqueous solution of a salt whichhas a metal ion other than an alkali metal ion, whereby the second metalsalt of the uracil derivative is manufactured. This embodiment generallyserves for the manufacture of uracil metal salts which are insoluble inwater.

The compounds of formula I, enol ethers as well as salts which areobtained can be isolated and purified according to methods known per se.Further, the sequence in which possible combinations of process variants(b) to (f) are conveniently carrried out in order to avoid possibleundesired concurrent reactions is familiar to the person skilled in theart.

Insofar as no planned synthesis for the isolation of pure isomers iscarried out, the product can result as a mixture of two or more isomers.The isomers can be separated according to methods known per se. Ifdesired, pure optically active isomers can also be manufactured, forexample, by synthesis from corresponding optically active startingmaterials.

The starting materials of formula II, which are novel, can be producedin a manner known per, e.g. in accordance with the following ReactionSchemes [methods (aa), (bb) and (cc)]: ##STR11##

In the above Reaction Scheme R³, R⁴, R⁵, R⁶, R⁷, R⁸, n and Q have thesignificances given above; R^(5') signifies hydrogen or C₁₋₄ -alkyl;R^(6') signifies C₁₋₄ -alkyl; and R¹⁰ signifies lower alkyl, preferablyC₁₋₄ -alkyl.

Method (aa) is conveniently carried out by reacting the compounds offormulae VIII and IX with each other in an essentially anhydrous diluentand in the presence of an acidic catalyst at an elevated temperature. Asdiluents there come into consideration especially organic solvents whichform azeotropes with water, such as aromatics, e.g. benzene, toluene andxylenes; halogenated hydrocarbons such as methylene chloride,chloroform, carbon tetrachloride and chlorobenzene; and aliphatic andcyclic ethers such as 1,2-dimethoxyethane, tetrahydrofuran and dioxan,and as acidic catalysts there especially come into consideration strongmineral acids such as sulphuric acid and hydrochloric acid; organicacids such as p-toluenesulphonic acid; phosphorus-containing acids suchas orthophosphoric acid and polyphosphoric acid; and acidic cationexchangers such as "Amberlyst 15" (Fluka). The reaction is generallycarried out in a temperature range of about 70° C. to 120° C.,preferably at the reflux temperature of the reaction mixture. Underthese reaction conditions the desired rapid removal of the water whichis formed in the reaction is achieved.

The reaction according to method (bb) is conveniently effected in thepresence of an essentially anhydrous aprotic organic solvent such as analiphatic or cyclic ether, e.g. diethyl ether, 1,2-dimethoxyethane,tetrahydrofuran or dioxan, an aliphatic or aromatic hydrocarbon. e.g.n-hexane, benzene, toluene or a xylene; or a halogenated, aliphatichydrocarbon, e.g. methylene chloride, chloroform, carbon tetrachlorideor 1,2-dichloroethane, as well as optionally in the presence of a base,especially an organic tertiary base such as triethylamine or pyridine,whereby the latter can serve not only as the solvent but also as thebase, or a metal hydride such as sodium hydride or potassium hydride.The reaction temperatures are preferably in the range of about -80° C.to 50° C., with the reaction being carried out particularly attemperatures between -30° C. and room temperature.

The reaction according to method (cc) is conveniently carried out in aninert, water-miscible, organic solvent such as an aliphatic or cyclicether, e.g. 1,2-dimethoxyethane, tetrahydrofuran or dioxan, or a loweralkanol such as ethanol at temperatures between 50° C. and 100° C.preferably at the reflux temperature of the reaction mixture, or in anaromatic solvent such as benzene toluene or a xylene in the presence ofan acidic catalyst such as hydrochloric acid or p-toluenesulphonic acidat temperatures between 50° C. and 100° C. preferably 60° C. to 80° C.

The starting materials of formulae III and V and their production arefor the most part described in European Patent Publication No. 195,346.Those starting materials III and V whose manufacture is not describedcan be produced analogously to the known starting materials. Thereactive derivatives of the benzoic acids of formula III, which canlikewise be used as starting materials, can be produced from thesebenzoic acids according to methods known per se. On the other hand allenol ethers of the benzoic acids III, i.e. the compounds of the generalformula ##STR12## which can likewise be used as starting materials inprocess variant (c), are novel. These can be produced, for example, inaccordance with the following Reaction Scheme in which R³, R⁴, R⁵, R⁶,R^(1'), R⁹, Hal and M.sup.⊕ have the significances given above:##STR13##

In the halogenation of the benzoic acid ester of formula XIII there isused as the halogenating agent especially thionyl chloride, phosphoruspentachloride or phosphorus oxychloride or phosphorus pentabromide orphosphoryl bromide. If desired, a mixture of phosphorus pentachlorideand phosphorus oxychloride or of phosphorus pentabromide and phosphorylbromide is used, in which case an excess of phosphorus oxychloride orphosphoryl bromide can serve as the diluent. The chlorination orbromination can be carried out in the presence of an inert diluent,especially an aprotic organic solvent such as an aliphatic or aromatichydrocarbon, e.g. n-hexane, benzene, toluene or a xylene; a halogenatedaliphatic hydrocarbon, e.g. methylene chloride, chloroform or1,2-dichloroethane; a halogenated aromatic hydrocarbon, e.g.chlorobenzene, or a tertiary amine, e.g. N,N-dimethylaniline, but thisis not necessary where phosphorus oxychloride or phosphoryl bromide isused as the halogenating agent. When thionyl chloride is used as thehalogenating agent it has been found to be convenient to add a catalyticamount of dimethylformamide. The reaction temperatures generally liebetween 0° C. and the reflux temperature of the reaction mixture,preferably between 80° C. and 120° C.

The reaction of the compound XIV with the compound VII can be effectedanalogously to process variant f) described above.

The subsequent hydrolysis of compound XV can be carried out according tomethods known per se, especially using an inorganic acid and optionallyin the presence of an organic solvent and/or of water. As acids therepreferably come into consideration hydrochloric acid, sulphuric acid andphosphoric acid, as organic solvents there preferably come intoconsideration alcohols, e.g. ethanol; aliphatic or cyclic ethers, e.g.1,2-dimethoxyethane, tetrahydrofuran and dioxan, and optionallychlorinated aliphatic or alicyclic hydrocarbons. e.g. methylenechloride, tetrachloromethane, n-hexane and cyclohexane. The reactiontemperatures generally lie between -20° C. and 120° C., preferablybetween 0° C. and 30° C. especially between 15° C. and 20° C.

The reactive derivatives of the enol ethers of the benzoic acids III,which can also be used as starting materials, can be produced from theseenol ethers according to methods known per se.

The starting materials of formula VI used in process variant f) can beproduced by halogenating the corresponding uracil derivatives of formulaI' given above analogously to the above-described process XIII→XIV (seethe Reaction Scheme and the description of the reaction conditionsfollowing therefrom).

The uracil derivatives of formula I' and I" which serve as startingmaterials in process variants (b) and (e) are sub-groups of compounds offormula I. The remaining starting materials and reagents which areinvolved in process variants (c), (d) and (f) as well as in the ReactionSchemes are either known or can be produced according to methods knownper se.

The compounds of formula I as well as their enol ethers or salts possessherbicidal properties and are suitable for the control of weeds,including weed grasses, especially Setaria faberii, Digitariasanguinalis, Poa annua, Chenopodium album, Amaranthus retroflexus,Abutilon theophriasti, Sinapsis alba and Datura stramonium, in diversecrop cultivations, especially in cereal, soya, maize, rice and cottoncultivations. Moreover, the compounds are not only pre-emergence, butalso post-emergence herbicides.

The compounds of formulae IIIa as well as their salts also possessherbicidal properties and can be used for the control of weed grassesand weeds especially the aforementioned, in a similar manner to thecompounds I. The novel compounds IIIa as well as their salts, weedcontrol compositions which contain these compounds as active substances,the above-defined process for the production of these compounds and theuse of these compounds or compositions for the control of weeds formfurther objects of the present invention. The salts of the compoundsIIIa are especially alkali metal salts, alkaline earth metal salts,ammonium salts and salts with organic bases such as are described abovein more detail in connection with the compounds I. The compounds IIIacan be converted into their salts just like the compounds I.Hereinafter, the compounds of formula I and their enol ethers or saltsas well as the compounds of formulae IIIa and their salts are denotedcollectively as compounds in accordance with the invention.

In practice, a concentration of 1 g to 3 kg of compound in accordancewith the invention/ha, preferably 10 to 500 g of compound in accordancewith the invention/ha, is usually sufficient to achieve the desiredherbicidal effect. The concentration range 15 to 100 g of compound inaccordance with the invention/ha is especially preferred.

The weed control composition in accordance with the invention ischaracterized in that it contains an effective amount of at least onecompound of formula I, as defined above, or of an enol ether or saltthereof or of a compound of formula IIIa or of a salt thereof as well asformulation adjuvants. The composition conveniently contains at leastone of the following formulation adjuvants: solid carrier substances;solvents or dispersion media; tensides (wetting and emulsifying agents);dispersing agents (without tenside action); and stabilizers. With theuse of these and other adjuvants these compounds, namely theherbicidally active substances can be converted into the usualformulations such as dusts. Powders, granulates, solutions, emulsions,suspensions, emulsifiable concentrates, pastes and the like.

The compounds of formula I. their enol ethers and the compounds offormulae IIIa are generally insoluble in water, whereas the salts,especially the alkali metal salts and ammonium salts, are generallysoluble in water, and can be formulated according to methods which areusual for water-insoluble or water-soluble compounds using therespective formulation adjuvants. The manufacture of the compositionscan be carried out in a manner known per se, e.g. by mixing theparticular active substance with solid carrier substances, bydissolution or suspension in suitable solvents or dispersion media, ifnecessary using tensides as wetting or emulsifying agents and/ordispersing agents, by diluting pre-prepared emulsifiable concentrateswith solvents or dispersion media etc.

As solid carrier substances there essentially come into consideration:natural mineral substances such as chalk, dolomite, limestone, aluminasand silicic acid and salts thereof (for example siliceous earth, kaolin,bentonite, talc. attapulgite and montmorillonite); synthetic mineralsubstances such as highly dispersible silicic acid, aluminium oxide andsilicates; organic substances such as cellulose, starch urea andsynthetic resins; and fertilizers such as phosphates and nitrates,whereby such carrier substances can be present e.g. as powders or asgranulates.

As solvents or dispersion media there essentially come intoconsideration: aromatics such as benzene toluene, xylenes andalkylnaphthalene; chlorinated aromatics and chlorinated aliphatichydrocarbons such as chlorobenzenes, chloroethylenes and methylenechloride; aliphatic hydrocarbons such as cyclohexane and paraffins, e.g.petroleum fractions; alcohols such as butanol and glycol, as well astheir ethers and esters; ketones such as acetone, methyl ethyl ketone,methyl isobutyl ketone and cyclohexanone; and strongly polar solvents ordispersion media such as dimethylformamide. N-methylpyrrolidone anddimethyl sulphoxide, such solvents preferably having flash points of atleast 30° C. and boiling points of at least 50° C. and water. Among thesolvents or dispersion media there also come into considerationso-called liquified gaseous extenders or carrier substances which arethose products which are gaseous at room temperature and under normalpressure. Examples of such products are especially aerosol propellantssuch as halogenated hydrocarbons, e.g. dichlorodifluoromethane. If theweed control composition in accordance with the invention is present inthe form of a pressurized pack, then a solvent is conveniently used inaddition to the propellant.

The tensides (wetting and emulsifying agents) can be non-ionic compoundssuch as condensation products of fatty acids fatty alcohols orfatty-substituted phenols with ethylene oxide; fatty acid esters andethers of sugars or polyvalent alcohols; the products which are obtainedfrom sugars or polyvalent alcohols by condensation with ethylene oxide;block polymers of ethylene oxide and propylene oxide; oralkyldimethylamine oxides.

The tensides can also be anionic compounds such as soaps; fatty sulphateesters, e.g. dodecyl sodium sulphate, octadecyl sodium sulphate andcetyl sodium sulphate; alkyl sulphonates, aryl sulphonates andfatty-aromatic sulphonates such as alkylbenzene sulphonates, e.g.calcium dodecylbenzenesulphonate, and butylnaphthalene sulphonates; andmore complex fatty sulphonates, e.g. the amide condensation products ofoleic acid and N-methyltaurine and the sodium sulphonates of dioctylsuccinate.

Finally, the tensides can be cationic compounds such asalkyldimethylbenzylammonium chlorides, dialkyldimethylammoniumchlorides, alkyltrimethylammonium chlorides and ethoxylated quaternaryammonium chlorides.

As dispersing agents (without tenside action) there essentially comeinto consideration; lignin, sodium and ammonium salts of ligninsulphonic acids, sodium salts of maleic anhydride-diisobutylenecopolymers, sodium and ammonium salts of sulphonated polycondensationproducts of naphthalene and formaldehyde, and sulphite lyes.

As dispersing agents, which are especially suitable as thickening oranti-settling agents, there can be used e.g. methylcellulose,carboxymethylcellulose, hydroxyethylcellulose, polyvinyl alcohol,alginates, caseinates and blood albumin.

Examples of suitable stabilizers are acid-binding agents. e.g.epichlorohydrin, phenyl glycidyl ether and soya epoxides; antioxidants,e.g. gallic acid esters and butylhydroxytoluene; UV-absorbers, e.g.substituted benzophenones diphenylacrylonitrile acid esters and cinnamicacid esters; and deactivators, e.g. salts of ethylenediaminotetraaceticacid and polyglycols.

The weed control compositions in accordance with the invention cancontain, in addition to the active substances in accordance with theinvention, synergists and other active substances, e.g. insecticides,acaricides, fungicides, plant growth regulators and fertilizers. Suchcombination compositions are suitable for intensifying the activity orfor broadening the spectrum of activity

The weed control compositions in accordance with the invention generallycontain between 0.001 and 95 weight percent, preferably between 0.5 and75 weight percent, of one or more compounds in accordance with theinvention as the active substance(s). They can be present e.g. in a formwhich is suitable for storage and transport. In such formulations. e.g.emulsifiable concentrates, the active substance concentration isnormally in the higher range, preferably between 1 and 50 weightpercent, especially between 10 and 30 weight percent. These formulationscan then be diluted, e.g. with the same or different inert substances,to give active substance concentrations which are suitable for practicaluse, i.e. preferably about 0.001 to 10 weight percent, especially about0.005 to 5 weight percent. The active substance concentrations can,however, also be smaller or greater.

As mentioned above, the manufacture of the weed control compositions inaccordance with the invention can be carried out in a manner known perse.

For the manufacture of pulverous preparations the active substance, i.e.at least one compound of in accordance with the invention, can be mixedwith a solid carrier substance, e.g. by grinding together; or the solidcarrier substance can be impregnated with a solution or suspension ofthe active substance and then the solvent or dispersion medium can beremoved by evaporation, heating or sucking-off under reduced pressure.By adding tensides or dispersing agents such pulverous preparations canbe made readily wettable with water, so that they can be converted intoaqueous suspensions which are suitable e.g. as spay compositions.

The active substance can also be mixed with a tenside and a solidcarrier substance to form a wettable powder which is dispersible inwater, or it can be mixed with a solid pre-granulated carrier substanceto form a product in the form of a granulate.

When desired, the active substance can be dissolved in awater-immiscible solvent such as, for example, a high-boilinghydrocarbon, which conveniently contains dissolved emulsifying agent, sothat the solution becomes self-emulsifying upon addition to water.Alternatively, the active substance can be mixed with an emulsifyingagent and the mixture can then be diluted with water to the desiredconcentration. Moreover, the active substance can be dissolved in asolvent and thereafter the solution can be mixed with an emulsifyingagent. Such a mixture can likewise be diluted with water to the desiredconcentration. In this manner there are obtained emulsifiableconcentrates or ready-for-use emulsions.

The use of the weed control compositions in accordance with theinvention which forms a further object of the present invention, can becarried out according to usual application methods such as sprinkling,spraying, dusting, watering or scattering. The method in accordance withthe invention for the control of weeds is characterized by treating thelocus to be protected against weeds and/or the weeds with a compound inaccordance with the invention or with a weed control composition inaccordance with the invention.

The following Examples serve to illustrate the invention in more detail.

I. Manufacture of the compounds of formula I: EXAMPLE 1

3.0 g of2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoicacid are heated at reflux temperature for 3 hours in 20 ml of benzeneand 2.9 ml of thionyl chloride together with 2 drops ofdimethylformamide. The reaction mixture is subsequently evaporated todryness and dissolved in 20 ml of dioxan. This solution, which consistsmainly of the acid chloride of the above-mentioned benzoic acid and thesolvent, is added dropwise to a solution of 0.86 g of 3-thietanol and1.0 g of pyridine in 10 ml of dioxan. The reaction mixture is thenstirred at room temperature for 2.5 hours, treated with 400 ml of waterand extracted twice with 400 ml of ethyl acetate each time. The combinedorganic phases are washed twice with 200 ml of 1N hydrochloric acid eachtime and once with 200 ml of saturated sodium chloride solution, driedover anhydrous sodium sulphate and evaporated. The residue is purifiedby chromatography on silica gel with ethyl acetate/n-hexane (2:3). Inthis manner there is obtained thietan-3-yl 2-chloro-5-[3,6-dihydro-26-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoatewhich can be recrystallized from ethyl acetate/n-hexane; m.p. 121°-123°C.

In an analogous manner, starting from2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoicacid via its acid chloride and:

cycloheptanol there is obtained cycloheptyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO. 400 MHz): 1.40-1.82 (m,10H), 1.94-2.04(m.2H), 3.41 (s,3H), 5.07-5.16 (m,1H), 6.61 (s,1H), 7.87 (d,1H), 8.00(d,1H);

3-hydroxytetrahydrofuran there is obtained tetrahydrofuran-3-yl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO, 400 MHz): 2.01-2.10 (m,1H), 2.20-2.31(m,1H), 3.42 (s,3H), 3.73-3.80 (m,1H), 3.82-3.91 (m,3H), 5.48-5.53(m,1H), 6.62 (s,1H), 7.89 (d,1H), 8.07 (d,1H);

5-hydroxy-1,3-dioxane there is obtained 1,3-dioxan-5-yl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO, 400 MHz): 3.42 (s,3H), 3.97-4.02 (m,2H),4.05-4.11 (m,2H), 4.78 (d,1H), 4.88-4.93 (m,2H), 6.62 (s,1H), 7.92(d,1H), 8.08 (d,1H); cyclopropylmethanol there is obtainedcyclopropylmethyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO, 400 MHz): 0.34-0.39 (m,2H), 0.54-0.60(m,2H), 1.16-1.24 (m,1H), 3.42 (s,3H), 4.15 (d,2H), 6.61 (s,1H), 7.90(d,1H), 8.05 (d,1H);

3-hydroxymethyl-3-methyl-oxetane there is obtained (3-methyl-3oxetanyl)methyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO, 400 MHz): 1.35 (s,3H), 3.42 (s,3H), 4.30(d,2H), 4.44 (s,2H), 4.48 (d,2H), 6.62 (s,1H), 7.90 (d,1H), 8.07 (d,1H);

2-tetrahydrofurylmethanol there is obtained tetrahydrofurfuryl2-chloro-5-[3,6-dihydro-2,6-dioxo-3methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate as an oil,¹ H-NMR (D₆ -DMSO, 400 MHz): 1.59-1.70 (m,1H), 1.76-1.90 (m,2H),1.93-2.04 (m,1H), 3.42 (s,3H), 3.62-3.69 (m,1H), 3.72-3.80 (m,1H),4.11-4.17 (m,1H), 4.21-4.33 (m,2H), 6.61 (s,1H), 7.90 (d,1H), 8.05(d,1H);

4-hydroxymethyl-1,3-dioxolane there is obtained(1,3-dioxolan-4-yl)methyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO, 400 MHz): 3.42 (s.3H), 3.67-3.72 (m,1H),3.96-4.04 (m,1H), 4.32-4.42 (m,3H), 4.83 (s,1H), 4.94 (s,1H), 6.62(s,1H), 7.91 (d,1H), 8.08 (d,1H);

benzyl alcohol there is obtained benzyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO. 400 MHz): 3.40 (s,3H), 5.37 (s,2H), 6.60(s,1H), 7.36-7.43 (m,3H), 7.47-7.50 (m,2H), 7.90 (d,1H), 8.08 (d,1H);

R-4,4-dimethyl-3-hydroxy-2-oxo-tetrahydrofuran there is obtained4,4-dimethyl-2-oxo-tetrahydrofuran-3-ylR-2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, [α]_(D) ²⁰ =-10.6°; ¹ H-NMR (D₆ -DMSO, 400 MHz): 1.11 (s,3H),1.22 (s,3H), 3.43 (s,3H), 4.13 (d,1H), 4.24 (d,1H), 5.89 (s,1H), 6.62(d,1H), 7.96 (d,1H), 8.15 (d,1H);

4-hydroxy-2,2,6,6-tetramethyl-tetrahydrothiopyran there is obtained2,2,6,6-tetramethyl-tetrahydrothiopyran-4-yl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO, 400 MHz): 1.25 (s,6H), 1.49 (s,6H), 1.61(t,2H), 2.19 (dd,2H), 3.42 (s,3H), 5.31-5.38 (m,1H), 6.62 (s,1H), 7.89(d,1H), 8.06 (d,1H);

cyclopentanol there is obtained cyclopentyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO. 400 MHz): 1.50-2.00 (m,8H), 3.42 (s,3H),5.31-5.38 (m,1H), 6.61 (s,1H), 7.87 (d,1H), 8.02 (d,1H);

phenol there is obtained phenyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO, 400 MHz): 3.43 (s,3H). 6.63 (s,1H),7.30-7.37 (m,3H), 7.45-7.53 (m,2H), 7.99 (d,1H), 8.39 (d,1H);

2-cyclohexylethanol there is obtained 2-cyclohexylethyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO, 400 MHz): 0.87-0.98 (m,2H), 1.10-1.25(m.3H), 1.32-1.45 (m,1H), 1.56-1.75 (m,7H), 3.42 (s,3H), 4.34 (t,2H),6.61 (s,1H), 7.89 (d,1H), 8.03 (d,1H);

1-cyclopropylethanol there is obtained 1-cyclopropylethyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO, 400 MHz): 0.34-0.45 (m,2H), 0.47-0.60(m,2H), 1.08-1.18 (m,1H), 1.38 (d,3H), 3.43 (s,3H), 4.55 (m.1H), 6.61(s,1H), 7.88 (d,1H), 8.01 (d,1H), mass spectrum (m/e): M⁺ 434(4);

p-methoxyphenol there is obtained p-methoxyphenyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,m.p. 128°-129° C., mass spectrum (m/e): M⁺ 472(24);

5-hydroxy-1,3-benzodioxol there is obtained 1,3-benzodioxol-5-yl2-chloro-5-[3,6-dihydro-2,6dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,m.p. 134°-135° C., mass spectrum (m/e): M⁺ 486(15);

2,4-dichlorobenzyl alcohol there is obtained 2,4-dichlorobenzyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,m.p. 88°-90° C.;

3-nitrobenzyl alcohol there is obtained 3-nitrophenyl-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,¹ H-NMR (D₆ -DMSO, 400 MHz): 3.41 (s,3H), 5.52 (s,2H), 6.60 (s,1H),7.70-7.74 (m,1H), 7.92 (d,1H), 7.95-7.98 (m,1H), 8.12 (d,1H), 8.20-8.26(m.1H), 8.37-8,39 (m,1H) mass spectrum (m/e): M⁺ 501(3);

cyclohexanol there is obtained cyclohexyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,¹ H-NMR (D₆ -DMSO, 400 MHZ): 1.27-1.59 (m,6H), 1.66-1.76 (m,2H),1.86-1.96 (m,2H), 3.39 (s,3H), 4.93-5.00 (m,1H), 6.61 (s,1H), 7.87(d,1H), 8.01 (d,1H); mass spectrum: (m/e): M⁺ 448(1);

3.5-bis-(trifluoromethyl)benzyl alcohol there is obtained3,5-bis(trifluoromethyl)phenyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,m.p. 129°-130° C.;

p-cyanophenol there is obtained p-cyanophenyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorbenzoate,¹ H-NMR (D₆ -DMSO, 400 MHz): 3.43 (s,3H), 6.63 (s,1H), 7.57-7.61 (m,2H),7.98-8.02 (m,3H), 8.42 (d,1H);

tetrahydrothiophen-3-ol there is obtained tetrahydrothien-3-yl2-chloro-5-[3,6-dihydro-2.6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,¹ H-NMR (D₆ -DMSO, 400 MHz): 1.98-2.09 (m,1H) 2.28-2.38 (m,1H),2.91-3.00 (m,3H), 3.18-3.24 (m,1H), 3.42 (s.3H), 5.66-5.73 (m,1H), 6.62(s,1H), 7.89 (d,1H), 8.03 (d,1H);

tetrahydropyran-4-ol there is obtained tetrahydropyran-3-yl2-chloro-5-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate.m.p. 173°-174° C.

2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane there is obtained(2,2-dimethyl-1,3-dioxolan-4-yl)methyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,¹ H-NMR (D6-DMSO, 400 MHz): 1.28 (s,3H), 1.33 (s,3H), 3.42 (s,3H),3.75-3.80 (m,1H), 4.02-4.10 (m.1H), 4.25-4.43 (m,3H), 6.61 (s,1H), 7.90(d,1H), 8.07 (d,1H);

In an analogous manner, starting from2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-benzoicacid via its acid chloride and 1-cyclopropylethanol there is obtained1-cyclopropylethyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-benzoate,m.p. 118°-119° C.;

In an analogous manner, starting from2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-pentafluoroethyl-1(2H)-pyrimidinyl]-4-fluorobenzoicacid via its acid chloride and tetrahydrofuran-3-ol there is obtained3-tetrahydrofuryl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-pentafluoroethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,¹ H-NMR (D₆ -DMSO, 400 MHz): 2.00-2.09 (m, 1H), 2.20-2.32 (m,1H), 3.43(s,3H), 3.74-3.92 (m,4H), 5.48-5.56 (m,1H), 6.50 (s,1H), 7.89 (d,1H),8.08 (d,1H);

In an analogous manner, starting from2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoicacid and

hydroxymethylcyclopropane there is obtained cyclopropylmethyl 2-chloro5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate,¹ H-NMR (CDCl₃, 400 MHz): 0.31-0.38 (m,2H), 0.57-0.64 (m,2H), 1.18-1.27(m,1H), 2.32 (s,3H), 3.45 (s,3H), 4.11-4.15 (m,2H), 5.74 (s.1H), 7.35(d,1H). 7.89 (d,1H); mass spectrum (m/e): M⁺ 366(13);

3-hydroxytetrahydrofuran there is obtained 3-tetrahydrofuryl2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate,m.p. 149°-151° C.;

1-cyclopropylethanol there is obtained 1-cyclopropylethyl2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO, 400 MHz): 0.33-0.43 (m,2H), 0.47-0.58(m,2H), 1.07-1.17 (m,1H), 1.37 (d,3H), 2.33 (s,3H), 3.35 (s,3H),4.49-4.57 (m,1H), 5.81 (s,1H), 7.82 (d,1H), 7.91 (d,1H); mass spectrum(m/e): M⁺ 380(8);

cyclopentanol there is obtained cyclopentyl2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoateas an oil, ¹ H-NMR (D₆ -DMSO. 400 MHz): 1.58-1.97 (m,8H), 2.33 (s,3H),3.35 (s,3H), 5.31-5.36 (m,1H), 5.80 (s,1H), 7.81 (d,1H), 7,91 (d,1H);mass spectrum (m/e): M⁺ 380(19);

EXAMPLE 2

3.4 g of 2-chloro-4-fluoro-5-[2-methoxy-6-oxo-4-trifluoromethyl-1(6H)pyrimidinyl]-benzoic acid are heated at reflux temperature for 3 hoursin 25 ml of benzene and 3.4 ml of thionyl chloride together with 2 dropsof dimethylformamide. The reaction mixture is subsequently evaporated todryness and dissolved in 20 ml of dioxan. This solution, which consistsmainly of the acid chloride of the above-mentioned benzoic acid and thesolvent, is added dropwise to a solution of 1.0 g of 3-thietanol and 1.3g of pyridine in 20 ml of dioxan. The reaction mixture is then stirredat room temperature for 3.5 hours, treated with 400 ml of water andextracted twice with 400 ml of ethyl acetate each time. The combinedorganic phases are washed twice with 200 ml of 1N hydrochloric acid eachtime and once with 200 ml of saturated sodium chloride solution, driedover anhydrous magnesium sulphate and evaporated. The residue ispurified by chromatography on silica gel with diethyl ether/n-hexane(1:2). In this manner there is obtained thietan-3-yl2-chloro-4-fluoro-5-[2-methoxy-6-oxo-4-trifluoromethyl-1(6H)-pyrimidinyl]-benzoateas a colourless oil, ¹ H-NMR(CDCl₃, 400 MHz): 3.37-3.44 (m,2H),3.57-3.66 (m,2H), 4.03 (s,3H), 5.85 (quintet, 1H), 6.63 (s,1H), 7.42(d,1H), 7.88 (d,1H).

In an analogous manner, from2-chloro-4-fluoro-5-[2-methoxy-6-oxo-4-trifluoromethyl-1(6H)-pyrimidinyl]-benzoicacid via its acid chloride and tetrahydrofuran-3-ol there is obtained3-tetrahydrofuryl2-chloro-4-fluoro-5-[2-methoxy-6-oxo-4-trifluoromethyl-1(6H)-pyrimidinyl]-benzoate,¹ H-NMR (D₆ -DMSO, 400 MHz): 2.02-2.10 (m,1H), 2.20-2.30 (m,1H),3.75-3.92 (m,4H), 3.96 (s,3H), 5.48-5.55 (m,1H), 6.86 (s,1H), 7.95(d,1H), 8.25 (d,1H), mass spectrum (m/e): M⁺ 436(2).

EXAMPLE 3

3.0 g of potassium2-chloro-4-fluoro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateand 0.6 ml of epichlorohydrin are heated at 70° C. for 3 hours in 25 mlof dimethylformamide. Thereafter, the reaction solution is added to 500ml of water and adjusted to pH 10 to 11 with a small amount of saturatedpotassium carbonate solution. It is extracted twice with 300 ml of ethylacetate. The organic phases are washed twice with 200 ml of water, driedover anhydrous magnesium sulphate and concentrated. The residue ispurified by chromatography on silica gel with ethyl acetate/n-hexane.There is obtained 2,3-epoxypropyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate as a pale yellowoil, ¹ H-NMR(D₆ -DMSO, 400 MHz): 2.73 (m,1H), 2.85 (m,1H), 32 (m,1H),3.42 (s,3H), 4.10 (m,1H), 4.69 (m,1H), 6.62 (s,1H), 7.92 (d,1H), 8.11(d,1H), mass spectrum (m/e): M⁺ 422(16).

EXAMPLE 4

103 g of chlorodifluoromethane are conducted into a suspension of 145.0g of isopropyl2-chloro-4-fluoro-5-[3,6-dihydro-2,6-dioxo-4-methyl-1(2H)-pyrimidinyl]-benzoateand 59.0 g of anhydrous, finely powdered potassium carbonate in 1 l ofdimethylformamide for 6 hours while stirring at 80° C. After cooling thesolid constituent is filtered off under suction and rinsed with 100 mlof dimethylformamide. The filtrate is concentrated to a large extentunder reduced pressure at 55° C., the residue is poured into 2 l ofwater and the aqueous mixture is adjusted to pH 3 with concentratedhydrochloric acid. The mixture is extracted with 1.5 l of ethyl acetateand the organic phase is washed twice with 1 l of water each time. driedover anhydrous sodium sulphate and evaporated to dryness under reducedpressure. The resinous residue is purified by chromatography on a silicagel column using ethyl acetate/n-hexane (1:1) as the eluent. The productis dissolved in 1500 ml of hot n-hexane and the solution is treated withcharcoal, filtered and concentrated to 700 ml at an elevatedtemperature. It is subsequently seeded and cooled to 5° C. whilestirring. The resulting crystals are filtered off under suction, washedwith n-hexane and dried. There is obtained isopropyl2-chloro-5-[3-difluoromethyl-3,6-dihydro-2,6-dioxo-4-methyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,m.p. 90°-93° C.

EXAMPLE 5-8

The corresponding uracil derivative of formula II is alkylated withchlorodifluoromethane analogously to the procedure described in Example4 in order to manufacture the compounds of formula I listed in thefollowing Table 1. ##STR14##

                  TABLE 1                                                         ______________________________________                                        Example                                                                              R.sup.3                                                                              R.sup.4                                                                              R.sup.6                                                                             Physical data                                      ______________________________________                                        5      Cl     F      C.sub.2 H.sub.5                                                                     .sup.1 H-NMR (CDCl.sub.3, 400 MHz):                                           7.83 ppm (d,1H), 7.74 ppm                                                     (t,1H), 7.36 ppm (d,1H), 5.90                                                 ppm (s,1H), 5.25 ppm (m,1H),                                                  2.87 ppm (q,2H), 1.36 ppm                                                     (d,6H), 1.31 ppm (t,3H).                           6      Br     F      C.sub.2 H.sub.5                                                                     .sup.1 H-NMR (CDCl.sub.3, 400 MHz):                                           7.81 ppm (d,1H), 7.74 ppm                                                     (t,1H), 7.57 ppm (d,1H), 5.90                                                 ppm (s,1H), 5.24 ppm (m,1H),                                                  2.87 ppm (q,2H), 1.37 ppm                                                     (d,6H), 1.32 ppm (t,3H).                           7      Br     F      CH.sub.3                                                                            .sup.1 H-NMR (CDCl.sub.3, 400 MHz):                                           7.80 ppm (d,1H), 7.72 ppm                                                     (t,1H), 7.57 ppm (d,1H), 5.83                                                 ppm (s,1H), 5.24 ppm (m,1H),                                                  2.49 pp (d,3H), 1.37 ppm                                                      (d,6H).                                            8      Cl     H      CH.sub.3                                                                            m.p. 115-117° C.                            ______________________________________                                    

EXAMPLE 9

A suspension of 2.00 g of2-chloro-5-[3-difluoromethyl-3,6-dihydro-2,6-dioxo-4-methyl-1(2H)-pyrimidinyl]-4-fluorobenzoic acid, 1.63 g of methyl iodide and0.61 g of sodium carbonate in 20 ml of acetone is heated at the boilingpoint for 4 hours. Subsequently, 1.63 g of methyl iodide are added and,after 2 hours, a further 1.63 g. The reaction mixture is heated atreflux temperature for a further 16 hours. After cooling insolubleconstituents are filtered off under suction and rinsed with acetone. andthe filtrate is evaporated to dryness under reduced pressure. Theresidue is dissolved in 100 ml of ethyl acetate and the solution iswashed twice with 100 ml of water each time. The organic phase is driedover anhydrous sodium sulphate and evaporated to dryness. The resinousresidue is purified by chromatography on a silica gel column usingdiethyl ether/n-hexane (1:2) as the eluent. The product isrecrystallized from diethyl ether/n-hexane. There is obtained methyl2-chloro- 5-[3-difluoro-methyl-3,6-dihydro-2,6-dioxo-4-methyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, m.p. 121°-123° C.

EXAMPLES 10-19

2-Chloro-5-[3-difluoromethyl-3,6-dihydro-2,6-dioxo-4-methyl-1(2H)-pyrimidinyl]-4-fluorobenzoicacid is appropriately esterified analogously to the procedure describedin Example 9 in order to manufacture the compounds of formula I listedin the following Table 2. ##STR15##

                  TABLE 2                                                         ______________________________________                                        Example                                                                              R.sup.2      Physical data                                             ______________________________________                                        10     C.sub.2 H.sub.5                                                                            M.p. 90-92° C.                                     11     nC.sub.3 H.sub.7                                                                           .sup.1 H-NMR (CDCl.sub.3, 400 MHz): 1.01                                      (t,3H), 1.77 (m,2H), 2.49 (s,3H),                                             4.28 (t,2H), 5.83 (s,1H), 7.37                                                (d,1H), 7.72 (t,1H), 7.87 (d,1H).                         12     nC.sub.4 H.sub.9                                                                           .sup.1 H-NMR (CDCl.sub.3, 400 MHz): 0.96                                      (t,3H), 1.44 (m,2H), 1.74 (m,2H),                                             2.49 (s,3H), 4.32 (t,2H), 5.83                                                (s,1H), 7.36 (d,1H), 7.72 (t,1H),                                             7.86 (d,1H).                                              13     sec. C.sub.4 H.sub.9                                                                       .sup.1 H-NMR (CDCl.sub.3, 400 MHz): 0.97                                      (t,3H), 134 (d,3H), 1.68 (m.2H),                                              2.50 (s,3H), 5.10 (m,1H), 5.83                                                (s,1H), 7.36 (d,1H), 7.72 (t,1H),                                             7.85 (d,1H).                                              14     isoC.sub.5 H.sub.11                                                                        .sup.1 H-NMR (CDCl.sub.3, 400 mHz): 0.95                                      (d,6H), 1.64 (q,2H), 1.75 (m,1H),                                             2.45 (s,3H). 4.35 (t,2H), 5.83                                                (s,1H), 7.36 (d,1H), 7.72 (t,1H),                                             7.85 (d,1H).                                              15     nC.sub.6 H.sub.13                                                                          .sup.1 H-NMR (CDCl.sub.3, 400 MHz): 0.89                                      (t,3H), 1.35 (m,6H), 1.75 (m,2H),                                             2.50 (s,3H), 4.31 (t,2H), 5.83                                                (s,1H), 7.36 (d,1H), 7.72 (t,1H),                                             7.86 (d,1H).                                              16     nC.sub.8 H.sub.17                                                                          .sup.1 H-NMR (CDCl.sub.3, 400 MHz): 0.88                                      (t,3H), 1.35 (m,10H), 1.74 (m,2H),                                            2.50 (s,3H), 4.31 (t,2H), 5.83                                                (s,1H), 7.36 (d,1H), 7.72 (t,1H),                                             7.86 (d,1H).                                              17     isoC.sub.4 H.sub.9                                                                         .sup.1 H-NMR (CDCl.sub.3, 400 MHz): 1.00                                      (d,6H), 2.07 (m,1H), 2.49 (s,3H),                                             4.11 (d,2H), 5.83 (s,1H), 7.37                                                (d,1H), 7.72 (t,1H), 7.87 (d 1H).                         18     CH.sub.2 CH═CH.sub.2                                                                   .sup.1 H-NMR (CDCl.sub.3, 400 MHz): 2.49                                      (s,3H), 4.81 (m,2H), 5.30 (m,1H)                                              5.39 (m,1H), 5.83 (s,1H), 6.00                                                (m,1H), 7.38 (d,1H), 7.71 (t,1H),                                             7.90 (d,1H).                                              19     CH.sub.2 OCH.sub.3                                                                         .sup.1 H-NMR (CDCl.sub.3, 400 MHz): 2.50                                      (s,3H), 3.54 (s,3H), 5.47 (s,2H),                                             5.83 (s,1H), 7.39 (d,1H), 7.72                                                (t,1H), 7.94 (d,1H).                                      ______________________________________                                    

EXAMPLE 20

A suspension of 2.00 g of2-chloro-5-[3-difluoromethyl-3,6-dihydro-2,6-dioxo-4-methyl-1(2H)-pyrimidinyl]-4-fluorobenzoic acid and 2.05 g of thionyl chloridein 25 ml of benzene is heated at reflux temperature for 20 hours. Theclear solution is evaporated to dryness under reduced pressure at 50°C., the residue is dissolved in 20 ml of methylene chloride andsubsequently stirred at room temperature for 3.5 hours with 5 ml ofpropargyl alcohol and 0.55 g of pyridine. The reaction mixture isevaporated to dryness under reduced pressure, the residue is dissolvedin 100 ml of ethyl acetate and the solution is extracted three timeswith 100 ml of water each time. The organic phase is dried overanhydrous sodium sulphate and evaporated to dryness. The resinousresidue is purified by chromatography on a silica gel column usingdiethyl ether/n-hexane (1:1) as the eluent. There is obtained propargyl2-chloro-5-[3-difluoromethyl-3,6-dihydro-2,6-dioxo-4 -methyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, ¹ H-NMR (CDCl₃, 400 MHz): 7.94 ppm(d, 1H), 7.71 ppm (t, 1H), 7.39 ppm (d, 1H), 5.83 ppm (s, 1H), 4.91 ppm(d, 2H), 2.52 ppm (t, 1H), 2.50 ppm (m, 3H).

EXAMPLES 21-25

2-Chloro-5-[3-difluoromethyl-3,6-dihydro-2,6-dioxo-4-methyl-1(2H)-pyrimidinyl]-4-fluorobenzoicacid is appropriately esterified analogously to the procedure describedin Example 20 in order to manufacture the compounds of formula I listedin the following Table 3. ##STR16##

                  TABLE 3                                                         ______________________________________                                        Example R.sub.2          Physical data                                        ______________________________________                                        21      C(CH.sub.3).sub.2 CH═CH.sub.2                                                              .sup.1 H-NMR (CDCl.sub.3,                                                     400 MHz): 1.65                                                                (s,6H), 2.49 (s,3H),                                                          5.15 (d,1H), 5.26                                                             (d,1H), 5.83 (s,1H),                                                          6.18 (m,1H), 7.34                                                             (d,1H), 7.72 (t,1H),                                                          7.78 (d,1H).                                         22      neo C.sub.5 H.sub.11                                                                           .sup.1 H-NMR (CDCl.sub.3,                                                     400 MHz): 1.02                                                                (s,9H), 2.50 (s,3H),                                                          4.03 (s,2H), 5.83                                                             (s,1H), 7.37 (d,1H),                                                          7.72 (t,1H), 7.87                                                             (d,1H).                                              23      (CH.sub.2).sub.2 C(CH.sub.3)(═CH.sub.2)                                                    .sup.1 H-NMR (CDCl.sub.3,                                                     400 MHz): 1.79                                                                (s,3H), 2.46 (m,5H),                                                          4.43 (t,2H), 4.78                                                             (s,1H), 4.83 (s,1H),                                                          5.83 (s,1H), 7.36                                                             (d,1H), 7.72 (t,1H),                                                          7.85 (d,1H).                                         24      tert. C.sub.4 H.sub.9                                                                          .sup.1 H-NMR (CDCl.sub.3,                                                     400 MHz): 1.58                                                                (s,9H), 2.49 (s,3H),                                                          5.83 (s,1H), 7.33                                                             (d,1H), 7.72 (t,1H),                                                          7.76 (d,1H).                                         25      cyclopentyl      .sup.1 H-NMR (D.sub.6 -DMSO,                                                  400 MHz): 1.55-1.82                                                           (m,6H), 1.90-2.00                                                             (m,2H), 2.44 (s,3H),                                                          5.35 (m,1H), 6.08                                                             (s,1H), 7.84 (d,1H),                                                          7.90 (t,1H), 8.08                                                             (d,1H).                                              ______________________________________                                    

EXAMPLE 26

A 55-60% suspension of 2.9 g of sodium hydride in mineral oil is placedin 30 ml of dimethylformamide and 2 ml of toluene and the mixture iscooled to 8°-0° C. while stirring. A solution of 12 g of ethyl3-axino-4,4,4-trifluorocarboxylate in 30 ml of dimethylformamide isadded dropwise. After completion of the addition the mixture is stirredat 5° C. for 1 hour. Subsequently, the mixture is cooled to an internaltemperature of -65° C. and a solution of 10 g of cyclopentyl2-chlorc-4-fluoro-5-isocyanatobenzoate in 30 ml of toluene is addeddropwise thereto. The reaction mixture is stirred at 31 65° C. for afurther 2.5 hours. Thereafter, 30 ml of cyclopentanol are added dropwisethereto and the reaction mixture is left to warm to room temperature. Itis acidified with 10 ml of glacial acetic acid and added to 500 ml ofwater and the resulting aqueous solution is extracted twice with 250 mlof ethyl acetate each time. The organic phases are combined, washed ineach case once with 200 ml of water and 200 ml of saturated sodiumchloride solution, dried over anhydrous magnesium sulphate andevaporated under reduced pressure. The residue is purified bychromatography on a silica gel column using ethyl acetate/n-hexane (1:3)as the eluent, and there is obtained in this manner cyclopentyl2-chloro-5-[3,6-dihydro-2,6-dioxo-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas a colourless oil. ¹ H-NMR (CDCl₃, 400 MHz): 1.50-2.05 (m,8H),5.34-5.48 (m,1H). 6.23 (s,1H), 7.36 (d,1H), 7.85 (d,1H); mass spectrum(m/e): M⁺ 420(1).

EXAMPLE 27

4.5 g of cyclopentyl2-chloro-5-[3.6-dihydro-2,6-dioxo-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,2.1 g of potassium bicarbonate and 1.5 ml of diethyl sulphate are heatedat reflux temperature in 50 ml of acetone for 4 hours. Subsequently. thesolvent is distilled off and the residue is partitioned in 150 ml ofdiethyl ether and 150 ml of water. The aqueous phase is extracted with afurther 150 ml of diethyl ether and the combined organic phases arewashed twice with 150 ml of water each time, dried over anhydrousmagnesium sulphate and concentrated. The residue is purified bychromatography on a silica gel column using ethyl acetate/n-hexane (1:4)as the eluent. In this manner there are obtained cyclopentyl2-chloro-5-[3-ethyl-3,6-dihydro-2,6-dioxo-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas a colourless oil, ¹ H-NMR (CDCl ₃, 400 MHz : 1 36 (t3H), 1.56-2.04(m,8H), 4.02 (q,2H), 5.36-5.45 (m,1H), 6.35 (s,1H), 7.36 (d,1H), 7.82(d,1H); mass spectrum (m/e): M⁺ 448 (1), as well as cyclopentyl2-chloro-5-[2-ethoxy-6-oxo-4-trifluoromethyl-1(6H)-pyrimidinyl]-4-fluorobenzoate,m.p. 90°-91° C.

EXAMPLE 28

A solution of 18.0 g of isopropyl2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate in 60 ml of methylene chloride is stirred intensivelyfor 5 minutes with 100 ml of concentrated sulphuric acid andsubsequently poured onto 1 kg of ice. The resulting crystals arefiltered off under suction. washed twice with 50 ml of water each timeand dissolved in 300 ml of methanol. The mother liquor is extractedtwice with 100 ml of methylene chloride each time and the organic phaseis washed with water to neutrality and combined with the methanolicsolution. This solution is dried over anhydrous sodium sulphate andevaporated to dryness. The crystalline residue is stirred with 100 ml ofethyl acetate at 70° C. and cooled to room temperature, and the crystalsare filtered off under suction and washed with diethyl ether. There isobtained 2-chloro-5-[3 -difluoromethyl-3.6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoic acid, m.p. 247°-248° C.

II Production of the benzoic acids III and of their enol ethers EXAMPLE29

A solution of 5 g of isopropyl2-chloro-4-fluoro-5-[2-methoxy-6-oxo-4-trifluoromethyl-1(6H)pyrimidinyl]-benzoate in 20 ml of methylene chloride is treated with 25ml of concentrated sulphuric acid while stirring and cooling at 20°-25°C. The reaction mixture is stirred at room temperature for a further 20minutes and poured on to 100 g of ice. The organic phase is separated,the aqueous phase is extracted twice with 15 ml of ethyl acetate eachtime and the combined organic phases are washed to neutrality withwater. The solution is subsequently dried over anhydrous sodium sulphateand evaporated to dryness under reduced pressure. The resinous residueis recrystallized from diethyl ether/n-hexane. There is obtained2-chloro-4-fluoro-5-[2-methoxy-6-oxo-4-trifluoromethyl-1(6H)-pyrimidinyl]-benzoic acid, m.p.205°-210° C.

In an analogous manner.

using isopropyl2-chloro-4-fluoro-5-[2-methoxy-6-oxo-4-pentafluoroethyl-1(6H)-pyrimidinyl]-benzoatethere is obtained2-chloro-4-fluoro-5-[2-methoxy-6-oxo-4-pentafluoroethyl-1(6H)-pyrimidinyl]-benzoicacid, m.p. 197°-199° C.;

using isopropyl2-chloro-4-fluoro-5-[5-fluoro-2-methoxy-6-oxo-4-trifluoromethyl-1(6H)-pyrimidinyl]-benzoatethere is obtained 2-chloro-4-fluoro-5-[5-fluoro-2-methoxy-6-oxo-4-trifluoromethyl-1(6H)-pyrimidinyl]-benzoic acid, m.p. 199°-201°C.;

using isopropyl 2-chloro-4-fluoro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-benzoatethere is obtained2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate.m.p. 239°-242° C.;

using isopropyl 2-chloro-5-[3.6-dihydro-2,6-dioxo-3-methyl-4trifluoromethyl-1(2H)-pyrimidinyl]-benzoate there is obtained2chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-benzoicacid, m.p. 235°-236° C.;

using isopopyl2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-pentafluoroethyl-1(2H)-pyrimidinyl]-4-fluorobenzoatethere is obtained2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-pentafluoroethyl-1(2H)-pyrimidinyl]-4-fluorobenzoicacid, m.p. 229°-231° C.;

using isopropyl2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoatethere is obtained2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoicacid, m.p. 236°-239° C.;

using isopropyl2-chloro-5-[2-methoxy-6-oxo-4-trifluoromethyl-1(6H)-pyrimidinyl]-benzoatethere is obtained 2-chloro-5-[2-methoxy-6-oxo-4trifluoromethyl-1(6H)-pyrimidinyl]-benzoic acid, m.p. 265°-268° C.

III. Production of the 3-Isocyanatobenzoic acid esters of formula XI:EXAMPLE 30

The cyclopentyl 2-chloro-4-fluoro-5-isocyanatobenzoate required as thestarting material in Example 26 can be 26 can be produced as follows:

A mixture of 100 g of 2-chloro-4-fluoro-5-nitrobenzoic acid, 50 ml ofthionyl chloride and 100 ml of benzene is heated at reflux temperaturefor 4 hours with the addition of 0.5 ml of dimethylformamide.Subsequently, the solvent is distilled off; crude2-chloro-4-fluoro-5-nitrobenzoyl chloride remains behind.

The 2-chloro-4-fluoro-5-nitrobenzoyl chloride is dissolved in 400 ml ofdioxan and the solution is added dropwise at room temperature whilestirring to a solution of 36 ml of cyclopentanol and 42 ml of pyridinein 300 ml of dioxan. After completion of the addition the mixture isstirred at room temperature for a further 4 hours, added to 300 g of iceand 300 ml of 2N hydrochloric acid and extracted twice with 300 ml ofethyl acetate each time.

The combined organic phases are washed once with 300 ml of 2Nhydrochloric acid and three times with 150 ml of saturated sodiumchloride solution each time, dried over anhydrous magnesium sulphate andconcentrated. After recrystallization from diisopropyl ether/n-hexanethere is obtained cyclopentyl 2-chloro-4-fluoro-5-nitrobenzoate, m.p.44°-45° C.

71 g of iron powder are placed in 190 ml of ethanol, 50 ml of water and5 ml of 32% hydrochloric acid while stirring and the whole is heated to75° C. (internal temperature). A warm solution of 100 g of cyclopentyl2-chloro-4-fluoro-5-nitrobenzoate in 50 ml of ethanol is added dropwiseto this mixture. The reaction mixture is stirred at 70°-75° C. (internaltemperature) for a further 2 hours, cooled, after cooling suctionfiltered over Celite and the residue on the suction filter is rinsedwith 500 ml of water followed by 200 ml of ethyl acetate. The filtrateis brought to a PH value of 8 with saturated potassium bicarbonatesolution and the resulting brown precipitate is filtered off overCelite. The filtrate is extracted twice with 400 ml of ethyl acetateeach time. the combined organic phases are washed twice with 200 ml ofsaturated sodium chloride solution each time, dried over anhydrousmagnesium sulphate and concentrated. Then, the residue is purified bychromatography on a silica gel column using ethyl acetate/n-hexane (1:4)as the eluent and crystallized from diisopropyl ether/n-hexane. In thismanner there is obtained cyclopentyl 5-amino-2-chloro-4-fluorobenzoate,m.p. 61°-62° C.

A solution of 19 g of cyclopentyl 5-amino 2chloro-4-fluorobenzoate in100 ml of ethyl acetate is added dropwise while stirring to a solution,warmed to 70° (internal temperature), of 9 ml of diphosgene in 40 ml ofethyl acetate. The reaction mixture is then heated at reflux temperaturefor 2 hours. Subsequently, the solvent is distilled off and the residueis distilled in a bulb tube under greatly reduced pressure. There isthen obtained cyclopentyl 2-chloro-4-fluoro-5-isocyanato-benzoate, b.p.160° C./0.06 mm Hg, which is required as the starting material inExample 26.

IV. Formulation Examples EXAMPLE 31

An emulsifiable concentrate contains the following ingredients:

    ______________________________________                                        Compound in accordance with the invention                                                               50     g/l                                          (active substance)                                                            N-Methylpyrrolidone (auxiliary solvent)                                                                 200    g/l                                          Nonylphenol-(10)ethoxylate (non-ionic                                                                   50     g/l                                          emulsifier)                                                                   Calcium dodecylbenzenesulphonate (anionic                                                               25     g/l                                          emulsifier)                                                                   Mixture of alkylbenzenes (solvent) ad                                                                   1000   ml                                           ______________________________________                                    

The active substance and the emulsifiers are dissolved in the auxiliarysolvent while stirring and the solution is made up to 1 liter with thesolvent.

The resulting emulsifiable concentrate can be emulsified in water andthen gives a ready-for-use spray liquor having the desiredconcentration.

EXAMPLE 32

The ingredients listed hereinafter are mixed with one another for themanufacture of a 25% spray liquor:

    ______________________________________                                        Compound in accordance with the invention                                                                25 g                                               (active substance)                                                            Silicic acid, hydrated (carrier material,                                                                5-25 g                                             grinding agent)                                                               Sodium lauryl sulphate (wetting agent)                                                                   1 g                                                Sodium lignosulphonate (dispersing agent)                                                                2 g                                                Kaolin (carrier material)  67-47 g                                                                       100 g                                              ______________________________________                                    

The mixture is subsequently finely ground using a pinned disc mill orcomparable milling apparatus.

Upon stirring in water the resulting spray powder gives a finesuspension which is suitable as a ready-for-use spray liquor.

We claim:
 1. Compounds of the formula ##STR17## wherein R¹ signifies hydrogen, C₁₋₄ -alkyl, C₃ or 4 -alkenyl, C₃ or 4 -alkynyl or C₁₋₄ -haloalkyl,R² signifies a group ##STR18## or, where R¹ signifies haloalkyl, also hydrogen C₁₋₈ -alkyl, C₂₋₈ -alkenyl, C₂₋₈ -alkynyl or C₂₋₈ -alkoxyalkyl, R³ signifies halogen or cyano, R⁴ signifies hydrogen or halogen, R⁵ signifies hydrogen, fluorine or C₁₋₄ -alkyl, R⁶ signifies C₁₋₄ -alkyl or C₁₋₄ -haloalkyl, the symbols R⁷ each independently signify hydrogen or C₁₋₃ -alkyl and n signifies 0, 1 or 2, and Q signifies a saturated three- to seven-membered carbocyclic or heterocyclic residue which is optionally substituted with one or more C₁₋₄ -alkyl residues, whereby the heterocyclic residue has 1 or 2 hetero atoms selected from oxygen and sulphur and optionally a keto function in the ring, Q signifies a phenyl residue which is optionally mono- or multiply-substituted with halogen, C₁₋₄ -alkyl, C₁₋₄ -haloalkyl, C₁₋₄ -alkoxy, C₁₋₄ -alkylthio, nitro and/or cyano and which additionally can bear a fused, saturated, carbocyclic or heterocyclic five- to seven-membered ring, whereby the heterocycle has 1 or 2 oxygen atoms in the ring,and the corresponding enol ethers of those compounds of formula I in which R¹ is different from hydrogen or C₁₋₄ -haloalkyl as well as alkali metal, alkaline earth metal, ammonium or organic base salts of those compounds of formula I in which R¹ or R² signifies hydrogen.
 2. Compounds according to claim 1, wherein R¹ signifies hydrogen, C₁₋₄ -alkyl, C₃ or 4 -alkenyl or C₃ or 4 -alkynyl, and their enol ethers and salts.
 3. Compounds according to claim 1, wherein R¹ signifies C₁₋₄ -haloalkyl, R² signifies hydrogen, C₁₋₈ -alkyl, C₂₋₈ -alkenyl, C₂₋₈ -alkynyl, C₂₋₈ -alkoxyalkyl or a group -(CR R)_(n) -Q and Q signifies either a saturated 3- to 7-membered carbocyclic or heterocyclic residue which is optionally substituted with one or more C₁₋₄ -alkyl residues, whereby the heterocyclic residue has 1 or 2 heteroatoms selected from oxygen or sulphur in the ring, or signifies a phenyl residue which is optionally mono- or multiply-substituted with halogen, C₁₋₄ -alkyl. C₁₋₄ -haloalkyl, C₁₋₄ alkoxy, C₁₋₄ -alkylthio, nitro and/or cyano, and the salts of these compounds.
 4. Compounds according to claim 2, wherein R¹ signifies methyl.
 5. Compounds according to claim 3, wherein R¹ signifies difluoromethyl.
 6. Compounds according to any one of claims 1 to 3, wherein R³ signifies chlorine or bromine and R⁴ signifies fluorine.
 7. Compounds according to any one of claims 1 to 3, wherein R³ signifies chlorine or bromine and R⁴ wherein R signifies hydrogen.
 8. Compounds according to any one of claims 1 to 3, wherein R⁵ signifies hydrogen. fluorine or methyl.
 9. Compounds according to any one of claims 1 to 3, wherein R⁶ signifies C₁₋₄ -alkyl.
 10. Compounds according to any one of claims 1 to 3, wherein R² signifies a group -(CR⁷ R⁷)_(n) -Q in which each R⁷ signifies hydrogen and n signifies 0 or
 1. 11. A compound according to claim 2, selected fromcycloheptyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, 3-tetrahydrofuryl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromerhyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,
 1. 3-dioxan-5-yl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate,cyclopropylmethyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, tetrahydrofurfuryl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, 1,3-dioxolan-4-ylmethyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, benzyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, 4,4-dimethyl-2-oxo-tetrahydrofuran-3-yl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, cyclopentyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, 1-cyclopropylethyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate and cyclohexyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate.
 12. A compound according to claim 3, selected fromisopropyl 2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, 2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoic acid, isopropyl 5-[4-ethyl-3-difluormethyl-3,6-dihydro-2,6-dioxo-1(2H)-pyrimidinyl]-2-chloro-4-fluorobenzoate, isopropyl 5-[4-ethyl-3-difluoromethyl-3,6-dihydro-2,6-dioxo-1(2H)-pyrimidinyl]-2-bromo-4-fluorobenzoate, isopropyl 2-bromo-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, 2-propynyl 2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate and methyl 2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate.
 13. A compound according to claim 1, selected fromcyclopropylmethyl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, 1-cyclopropylethyl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]4-fluorobenzoate, cyclopentyl 2-chloro-5-[3,6-dihydro 3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, cyclohexyl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, cycloheptyl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo- 1(2H)-pyrimidinyl]-4-fluorobenzoate, 3-tetrahydrofuryl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]4-fluorobenzoate, 1,3-dioxan-5-yl 2-chloro-5-[3,6 dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl-]-4-fluorobenzoate, (1,3 dioxolan-4-yl)methyl 2-chloro-5 [3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, benzyl 2-chloro 5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate and tetrahydrofurfuryl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate.
 14. Compounds of the formula: ##STR19## wherein R¹ ' signifies C₁₋₄ -alkyl, C₃ or 4 -alkenyl or C₃ or 4 -alkynyl,R³ signifies halogen or cyano, R⁴ signifies hydrogen or halogen, R⁵ signifies hydrogen, fluorine or C₁₋₄ -alkyl and R⁶ signifies C₁₋₄ -alkyl or C₁₋₄ -haloalkyl,as well as the alkali metal, alkaline earth metal, ammonium or organic base salts thereof.
 15. A weed control composition, characterized in that it contains an effective amount of at least one compound of the formula ##STR20## wherein R¹ signifies hydrogen, C₁₋₄ -alkyl, C₃ or 4 -alkenyl, C₃ or 4 -alkynyl or C₁₋₄ -haloalkyl,R² signifies a group ##STR21## or, where R¹ signifies haloalkyl, also hydrogen, C₁₋₈ -alkyl, C₂₋₈ -alkenyl, C₂₋₈ -alkynyl or C₂₋₈ -alkoxyalkyl, R³ signifies halogen or cyano, R⁴ signifies hydrogen or halogen, R⁵ signifies hydrogen, fluorine or C₁₋₄ -alkyl, R⁶ signifies C₁₋₄ -alkyl or C₁₋₄ -haloalkyl, the symbols R⁷ each independently signify hydrogen or C₁₋₃ -alkyl and n signifies 0, 1 or 2, and Q signifies a saturated three- to seven-membered carbocyclic or heterocyclic residue which is optionally substituted with one or more C₁₋₄ -alkyl residues, whereby the heterocyclic residue has 1 or 2 hetero atoms selected from oxygen and sulphur and optionally a keto function in the ring, or Q signifies a phenyl residue which is optionally mono- or multiply-substituted with halogen, C₁₋₄ -alkyl, C₁₋₄ -haloalkyl, C₁₋₄ -alkoxy, C₁₋₄ -alkylthio, nitro and/or cyano and which additionally can bear a fused, saturated, carbocyclic or heterocyclic five- to seven-membered ring, whereby the heterocycle has 1 or 2 oxygen atoms in the ring,or of an enol ether of such a compound I in which R¹ is different from hydrogen or C₁₋₄ -haloalkVl or of an alkali metal, alkaline earth metal, ammonium or organic base salt of such a compound I in which R¹ or R² is hydrogen, as well as formulation adjuvants.
 16. A weed control composition according to claim 15, characterized in that it contains an effective amount of at least one compound selected from the groupcycloheptyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4fluorobenzoate, 3-tetrahydrofuryl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, 1,3-dioxan-5-yl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, cyclopropylmethyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl 4 trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, tetrahydrofurfuryl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl 1(2H)-pyrimidinyl]-4-fluorobenzoate, 1,3-dioxolan-4-ylmethyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, benzyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, 4,4-dimethyl-2-oxo-tetrahydrofuran-3-yl 2-chloro-5-[3,6-dihydro-2,6 dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, cyclopentyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate, 1-cyclopropylethyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoate and cyclohexyl 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoateas well as formulation adjuvants.
 17. A weed control composition according to claim 15, characterized in that it contains an effective amount of at least one compound selected from the groupisopropyl 2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, 2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoic acid, isopropyl 5-[4-ethyl-3-difluormethyl-3,6-dihydro-2,6-dioxo-1(2H)-pyrimidinyl]-2-chloro-4-fluorobenzoate, isopropyl 5-[4-ethyl-3-difluoromethyl-3,6-dihydro-2,6-dioxo-1(2H)-pyrimidinyl]-2-bromo-4-fluorobenzoate, isopropyl 2-bromo-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, 2-propynyl 2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate and methyl 2-chloro-5-[3-difluoromethyl-3,6-dihydro-4-methyl 2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoateas well as formulation adjuvants.
 18. A weed control composition according to claim 15, characterized in that it contains an effective amount of at least one compound selected from the groupcyclopropylmethyl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, 1-cyclopropylethyl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, cyclopentyl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, cyclohexyl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, cycloheptyl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, 3-tetrahydrofuryl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, 1,3-dioxan-5-yl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, (1,3-dioxolan-4-yl)methyl 2-chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate, benzyl 2-chloro-5-[3,6-dihydro 3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoate and tetrahydrofurfuryl 2 chloro-5-[3,6-dihydro-3,4-dimethyl-2,6-dioxo-1(2H)-pyrimidinyl]-4-fluorobenzoateas well as formulation adjuvants.
 19. A weed control composition, characterized in that it contains an effective amount of at least one compound of the formula ##STR22## wherein R¹ ' signifies C₁₋₄ -alkyl, C₃ or 4 -alkenyl or C₃ or 4 -alkynyl,R³ signifies halogen or cyano, R⁴ signifies hydrogenor halogen, R⁵ signifies hydrogen, fluorine or C₁₋₄ -alkyl and R⁶ signifies C₁₋₄ -alkyl or C₁₋₄ -haloalkyl, or of an alkali metal, alkaline earth metal, ammonium or organic base salt thereof, as well as formulation adjuvants. 